1. Field of the Invention
The present invention relates to a radiator unit for an internal combustion engine and, more particularly, to a radiator unit to be used in combination with a cooling fan included in an internal combustion engine and a method of combining the same with the engine.
2. Description of the Related Art
A conventional radiator unit for an automotive internal combustion engine (hereinafter referred to simply as xe2x80x9cenginexe2x80x9d) has a radiator core mounted on a car body, and a fan shroud attached to the radiator core so as to surround a cooling fan mounted on the engine.
When shipping a general-purpose liquid-cooled engine, the liquid-cooled engine is not provided with any radiator unit in most cases. If the user desires, a radiator unit as an option is combined with the liquid-cooled engine before shipping the liquid-cooled engine.
In an engine provided with a radiator unit 10 as shown in FIG. 7, a radiator core 102 is fixedly provided with a fan shroud 101 surrounding a cooling fan 100, and the radiator core 102 is fixed on the engine via upper and lower brackets (not shown) with bolts. An L-shaped intake duct 110 is connected to the air inlet 106 of an air cleaner 105.
Combining the radiator unit 10 with the engine with the bolts as shown in FIG. 7 takes much time and labor because the heavy radiator core 102 must be positioned so that an appropriate clearance is formed between the fan shroud 101 attached to the radiator core 102, and the fan 100. Further, since the fan shroud 101 is attached directly to the radiator core 102, the fan shroud 101 vibrates together with the heavy radiator core 102. Consequently, the position of the fan shroud 101 relative to the cooling fan 100 mounted on the engine changes, noise may be generated or the fan shroud 101 may come into contact with the cooling fan 100.
In many cases, as shown in FIG. 7, the intake duct 110 connected to the air inlet 106 of the air cleaner 105 is opened toward the front side of the radiator unit 10 to take in not heated air. In this case, it is desirable that the intake duct 110 is extended so as to avoid the radiator unit 10 and to extend toward the front side of the radiator unit 10. Thus, the intake duct 110 extends beyond the radiator unit 10, which increases the outside dimensions of the engine.
The present invention has been made in view of such problems and it is therefore an object of the present invention to provide a radiator unit having a radiator core and a fan shroud capable of being easily attached to and detached from an engine and of enabling an intake duct to open toward the front side of the radiator core without increasing the outside dimensions of the engine.
According to a first aspect of the present invention, a radiator unit to be used in combination with a cooling fan mounted on an engine includes a radiator support member attached to the engine; and a radiator core fastened to the radiator support member; wherein a lower end part of the radiator core is connected to a lower end part of the radiator support member by a plug-in structure including a positioning pin provided on the lower end part of the radiator core and a positioning hole of a positioning lug provided in the radiator support member, and an upper end part of the radiator core is fastened to an upper end part of the radiator support member.
Preferably, the radiator unit according to the first aspect of the present invention further includes a fan shroud attached to the radiator support member so as to surround the cooling fan. Preferably, an intake duct connected to the air inlet of an air cleaner mounted on the engine is formed integrally with the fan shroud.
Preferably, the lower end part of the radiator core is connected to the lower end part of the radiator support member through a damping member. Also, it is preferable that the upper end part of the radiator core is connected to the upper end part of the radiator support member through a damping member.
According to a second aspect of the present invention, a radiator unit to be used in combination with a cooling fan mounted on an engine includes a radiator support member attached to the engine; a radiator core fastened to the radiator support member; and a fan shroud attached to the radiator support member so as to surround the cooling fan; wherein an intake duct connected to the air inlet of an air cleaner mounted on the engine is formed integrally with the fan shroud.
According to a third aspect of the present invention, a radiator-engine combining method of combining a radiator unit with an engine includes the steps of fastening a radiator support member to the engine; attaching a fan shroud to the radiator support member so as to surround a cooling fan mounted on the engine; and attaching a radiator core to the radiator support member by connecting a lower end part of the radiator core to a lower end part of the radiator support member by a plug-in structure including a positioning pin provided on the lower end part of the radiator core and a positioning hole of a positioning lug provided in the radiator support member, and fastening an upper end part of the radiator core to an upper end part of the radiator support member with a bolt.
Preferably, the step of attaching the fan shroud to the radiator support member of the method according to the third aspect of the present invention connects an intake duct formed integrally with the fan shroud to the air inlet of an air cleaner mounted on the engine.
According to the first and the third aspect of the present invention, the radiator support member is fixed to the engine, the lower end part of the radiator unit is engaged with the lower end part of the radiator support member by the plug-in structure including the pin and the positioning lug and the upper end of the radiator unit is fastened to the upper end part of the radiator support member with the bolt. Thus, the radiator core can be easily positioned, only the upper end part of the radiator unit needs to be fastened to the radiator support member with the bolt and hence the radiator can be easily combined with the engine.
According to the first and the second aspect of the present invention, the fan shroud for surrounding the cooling fan mounted on the engine is not fixed directly to the radiator core and is fixed individually to the radiator support member attached to the engine. Thus, the fan shroud can be easily positioned and fixed to the radiator support member such that an appropriate clearance is maintained between the fan shroud and the cooling fan. Since the clearance between the fan shroud and the cooling fan remains constant even if the heavy radiator core vibrates, noise will not be generated and the cooling fan will not touch the fan shroud.
According to the first to the third aspect of the present invention, the intake duct connected to the air inlet of the air cleaner is formed integrally with the fan shroud that is fastened to the radiator support member supporting the radiator unit, so that the number of parts can be reduced, the fan shroud and the intake duct can be simultaneously mounted on the engine and work for assembling the engine is simplified. Since the fan shroud is formed integrally with the intake duct, the intake duct can be easily disposed close to the periphery of the radiator core and can be extended to the front side of the radiator unit without increasing the outside dimensions of the engine.